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If necessary optimize by alternating with optical focus adjustment.Ģ、With unchanged optical focus adjustment and shortest focal length adjust the red and blue pick-up tube until optimum focus is achieved.
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With shortest focal length and divergent focus adjust the pick-up tube in W-channel until optimum focus is achieved. Set optical focus at greatest focal length. With the aid of a low transmission filter and by means of low level lighting make sure that the camera is not over modulated with the aperture in the open position.Ī) Optical focus: Adjust focus of zoom lens at greatest focal length.ī) Back focal distance (lens): Adjust focus at shortest focal length by regulating lens mechanically with adjustment screw and optimize alternatively with a).Ĭ) Back focal distance (pick-up tubes): If focus varies from channel to channel between greatest and shortest focal length, the individual pick-up tubes must be adjusted mechanically in the optical axis.ġ、Select white channel. It shows a 36 sector Siemens star on a white background. The YE0120 test chart is designed for the adjustment of camera lenses and checking back focal distance.
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